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Unloader valve for hydrostatic units

IP.com Disclosure Number: IPCOM000012769D
Publication Date: 2003-May-28

Publishing Venue

The IP.com Prior Art Database


The parking brake systems of skid steer loaders not capable of restraining the drive system when the motors are driven with full system pressure. Simultaneous actuation of the brake and propel controls commonly happens when the hydrostatic pump is of the manual displacement control type. For many mobile hydrostatic applications utilizing manual displacement pumps, it is expensive and impractical to design a system of locking the displacement controls from use when the brake is actuated. Remote mounting of a valve for the same purpose as the unloader valve is expensive and introduces several expensive and failure prone fittings and hoses.